JPH11156998A - Laminated metal plate and metal container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a remarkable deterioration of an external appearance due to generation of rust of a metal can material and prevent migration of rust component to foods by laminating a film for laminating a metal plate containing a thermoplastic resin having no pinhole of specific diameter or more in a part to be laminated at least one a metal. SOLUTION: A film is necessary that a pinhole of 0.1 mm or more of a diameter is not existed in a part to be laminated at least on a metal. If the pinhole has 0.1 mm or less in diameter, the pinhole is blocked by an infinitesimal dimensional change or fluidization due to a heat history of the film at the time of laminating by a thermal press bonding to a metal plate, and rust preventive characteristics of a metal can material can be maintained. All pinholes of 0.1 mm in diameter can be detected by a pinhole detector of a high voltage application type. And, lamination of the film of the metal plate may be on one side surface of both side surface. A metal container is obtained by molding by using a laminated metal plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated metal plate laminated with a laminating film used for heat resistance, cosmetics and rust prevention of metal cans such as soft drinks, beer and cans, and the laminated metal plate. And a metal container obtained by molding the same into a can shape.

[0002]

2. Description of the Related Art Conventionally, a paint is generally applied to prevent corrosion of an inner surface and an outer surface of a metal can, and a thermosetting resin is used for the paint. As another method, there is a method using a thermoplastic resin. For example, attempts have been made to laminate a polyolefin-based film on heated tin-free steel. Further, it has been studied to laminate a polyester film having good heat resistance on a metal plate and use the laminated metal plate for a metal can.

[0003] Most of thermosetting resin coatings are of a solvent type,
Heating at 150 to 250 ° C. for a few minutes at a high temperature for a long time is necessary for forming the coating film. In addition, since a large amount of organic solvent is scattered during baking, improvements such as simplification of processes and prevention of pollution are demanded. In addition, even when applied under the above conditions, it is inevitable that a small amount of organic solvent remains in the coating film.For example, when a food can is filled in a metal can formed with the coating film, The organic solvent migrates to foodstuffs and adversely affects the taste and smell of the foodstuffs. Furthermore, additives contained in the paint and low molecular weight substances resulting from incomplete crosslinking reaction migrate to foodstuffs, and have the same adverse effects as residual organic solvents.

[0004] Among the above problems, problems such as simplification of the process and prevention of pollution can be solved by a method using a thermoplastic resin film. In particular, a method using a polyester film among thermoplastic resin films is the most preferable method.

[0005] That is, the polyester-based film is excellent in heat resistance, does not require additives such as a heat stabilizer, and has a low generation of low molecular weight substances. This can be said to be a suitable measure against the problem of the taste and smell of foodstuffs due to the migration of additives and low molecular weight substances to be produced.

[0006]

However, when a thermoplastic resin film represented by a polyester film is laminated on a metal plate and the laminated metal plate is used for a metal can, a pinhole (hole) is formed in the film. When metal is present, a corrosion phenomenon occurs in the metal can material, sharply impairing the clarity and aesthetic appearance of the trademark printing on the outer surface of the metal can, and oxides (rust) of the metal can material on the inner surface of the metal can cause food products. Which can have a significant adverse effect on the taste and smell of foodstuffs, as well as on human health.

An object of the present invention is to provide a metal plate on which a film having no pinholes and excellent in corrosion resistance has been laminated, in which the above problems have been solved. further,
Another object of the present invention is to provide a metal container having excellent corrosion resistance.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above-mentioned object, and as a result, the pinholes existing in the thermoplastic resin film have a size of 0.1 m.
The inventors have found that there must not be any of mφ or more, and have completed the present invention. That is, the present invention relates to a laminated metal plate obtained by laminating a film for laminating a metal plate containing a thermoplastic resin having no pinhole having a diameter of 0.1 mmφ or more at least in a portion to be laminated to a metal. The present invention also relates to a metal container formed by using the above-mentioned laminated metal plate.

In a preferred embodiment, the thermoplastic resin of the laminating film used in the present invention is a polyester resin. Further, the surface tension of at least one surface of the thermoplastic resin film is preferably 420 μN or more, and the shrinkage of the film after the heat treatment at 150 ° C. for 30 minutes in the longitudinal and transverse directions is 5% or less, respectively. Is a preferred embodiment.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The film of the present invention is characterized in that at least a portion to be laminated to a metal has no pinhole having a diameter of 0.1 mmφ or more. That is,
The present inventors have found that if the pinhole is less than 0.1 mmφ, for example, during lamination by thermocompression bonding to a metal plate, a minute dimensional change phenomenon due to the heat history of the film was present immediately before lamination as a result. The microhole phenomenon caused by the heat history during lamination of the adhesive and / or the adhesive layer existing between the film and the metal plate due to the blockage of the pinhole, and as a result, the pinhole that existed immediately before the lamination was closed. Furthermore, they have found that the rust-preventive properties of the metal can material can be maintained. In order to achieve the above object, it is necessary that a pinhole having a diameter of 0.1 mmφ or more does not exist at least in a portion of the film to be laminated on a metal. In particular, regardless of the size of the film production lot, in other words, whether it is a small lot, a medium lot, or a large lot, the film of one production lot has no pinholes with a diameter of 0.1 mmφ or more. It is desirable. That is, a diameter of 0.1
Pin number of holes above mmφ is 0 defects / 1,000 m ² or less, 0 defects / 10,00M ² or less, 0 defects / 100,000
m ² or less, 0 Ke / ∞m ² is preferred.

The pinhole is detected by a pinhole detector using a high voltage application method. According to the method, 0.1
All pinholes of mmφ or more can be detected. Diameter 0.
A detector capable of detecting all pinholes exceeding 01 mmφ is preferable.

FIG. 1 shows an example of a pinhole detector of a high voltage application type according to the present invention. The film sample roll wound into a roll attached to the first unwinding shaft is unwound toward the second guide roller and runs. When the film travels between the detection unit roller in the next 3 and the detection electrode 4 set on the detection unit roller, a discharge phenomenon occurs from the detection electrode if a pinhole exists in the film. The structure is such that the presence of a pinhole is detected by a high-voltage generator and a pinhole detection data processing device. Thereafter, the film travels between the guide roller 5 and the pressing roller 6 and is wound on a core attached to a winding shaft 7. Such a pinhole detector may be installed online or offline for the film manufacturing process,
An online installation is more preferable.

In order to eliminate pinholes having a diameter of 0.1 mm or more, it is necessary to sufficiently dry the raw materials for film production in producing a thermoplastic resin film. For example,
When a polyester resin is used as the thermoplastic resin, the moisture content in the raw material must be 50 ppm or less. If it exceeds 50 ppm, air bubbles are mixed during the film production process, and the air bubbles are destroyed and become pinholes during the course of various subsequent processing steps, which is not preferable.

In the production of a thermoplastic resin film,
In the resin melting step for forming into a film,
It is necessary to sufficiently remove degraded resin and other contaminant components. For example, at least one site having a filter function must be introduced during the process. When a thermoplastic resin film is manufactured in a resin melting process without a portion having a filter function, foreign matter such as contaminants is generated as a nucleus in the film. It is not preferable because it breaks down as it passes and becomes a pinhole.

Further, the manufacturing process of the thermoplastic resin film is always in a clean state, that is, on the film surface.
In addition, care must be taken to maintain a state where there is no floating foreign matter that may adhere. When a large amount of floating foreign matter is present in the manufacturing process of the thermoplastic resin film, the floating foreign matter gets on or adheres to the film. For example, in the film winding step, the floating foreign matter is caught together with the film, and the film is wound. Undesirably, the floating foreign matter makes a hole in the film due to the film tension and / or the pressing force at the time, and becomes a pinhole.
Using a pinhole detector, the quality of the film to be manufactured is inspected, and the product is classified according to the number of pinholes.

As the thermoplastic resin, a polyester resin is preferable, and the polyester resin is mainly obtained by polycondensation of a polycarboxylic acid and a polyhydric alcohol. Examples of the polycarboxylic acid component include dicarboxylic acids, for example, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, and diphenyldicarboxylic acid; adipic acid, azelaic acid, sebacic acid, decanedicarboxylic acid And aliphatic dicarboxylic acids such as dodecane dicarboxylic acid and dimer acid; and alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid.

[0017] Among the above, especially when the above film is used on the inner surface of the metal container, the protective effect of the foodstuff to be filled,
From the viewpoint of so-called flavor resistance, use of an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid is preferred. Examples of the polyhydric alcohol component include glycols, for example, aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propane diol, butane diol, hexane diol, dodecane methylene glycol, and neopentyl glycol; and fats such as cyclohexane dimethanol. Cyclic diols; and aromatic diols such as ethylene oxide adducts of bisphenol derivatives. Preferably, it is ethylene glycol.

As the polyester, polyethylene terephthalate or a composition containing polyethylene terephthalate and a polyester-polyol block copolymer in an amount of 0.6 to 6% by weight in terms of a polyether component is particularly recommended. This configuration is preferable because the whitening phenomenon of the film caused by hot water treatment such as retort treatment is suppressed.

In the polyester, it is preferable that at least 70 mol% of the constituent components be composed of ethylene terephthalate units, more preferably 80 mol%.
That is all.

Ethylene terephthalate unit is 70 mol%
With the above, the heat resistance hardly decreases, for example, when the film is laminated on a metal can material, the film is stretched, the width of the film shrinks due to heat shrinkage, wrinkles are less likely to occur, and the laminating conditions are mild. There is almost no need for the polyester resin, and there is almost no economical disadvantage due to the increased raw material cost of the polyester.

The polyester is, from the viewpoint of mechanical properties,
The intrinsic viscosity is preferably 0.5 or more, more preferably 0.55 to 0.85.

In addition, the thermoplastic resin is made of inorganic particles and / or so as to impart slipperiness and scratch resistance during can making.
Alternatively, it is a preferred embodiment to appropriately mix crosslinked polymer particles, or to make the polyester contain at least one component selected from thermoplastic resins incompatible with the polyester when the resin is a polyester. The above components may be used alone or in combination of two or more, but a combined system is preferred.

The inorganic fine particles are not particularly limited as long as they are insoluble and inactive in the thermoplastic resin. Specifically, metal oxides such as silica, alumina, zirconia and titanium oxide; complex oxides such as kaolin, zeolite, sericite and sepiolite; sulfates such as calcium sulfate and barium sulfate; calcium phosphates and zirconium phosphate Phosphates; carbonates such as calcium carbonate; These inorganic fine particles may be either natural products or synthetic products, and the shape of the particles is not particularly limited. The inorganic fine particles may be used alone or in combination of two or more. In the case where only inorganic fine particles are used, a combined system of aggregated amorphous silica and spherical silica or zeolite is preferable.

The material of the crosslinked polymer particles is not particularly limited as long as it has heat resistance that can withstand the temperature during melt molding of the thermoplastic resin. For example, acrylic monomers such as acrylic acid, methacrylic acid, acrylic esters, and methacrylic esters; styrene monomers such as styrene and alkyl-substituted styrene; and divinylbenzene, divinylsulfone, and ethylene glycol dimethacrylate. Acrylate, trimethylolpropane trimethyl acrylate,
Copolymers with a crosslinkable monomer such as pentaerythritol tetramethyl acrylate; melamine resins; benzoguanamine resins; phenol resins; silicone resins. Among the above materials, a copolymer of an acrylic monomer and / or a styrene monomer and a crosslinkable monomer is particularly preferred. The crosslinked polymer particles may be used alone or in combination of two or more.

The method for producing the above-mentioned crosslinked polymer particles is not particularly limited, and can be produced by a conventionally known emulsion polymerization method, suspension polymerization method or the like. In addition, there is no restriction on incorporating means such as pulverization and classification for adjusting the particle diameter and the particle size distribution of the crosslinked polymer particles.

Examples of the thermoplastic resin incompatible with polyester include polyolefin resin, polystyrene resin, polyacrylic resin, polycarbonate resin, polyamide resin, polysulfonic acid resin, wholly aromatic polyester resin and the like. Can be The thermoplastic resins may be used alone or in combination of two or more. The resin does not need to be in the form of particles.

The addition of the thermoplastic resin incompatible with the inorganic fine particles, the crosslinked polymer particles, and the polyester may be carried out in the process of producing the thermoplastic resin, or may be carried out by melt-kneading the thermoplastic resin and the above components. You can go by law. Further, it can be added as a master batch containing the above components at a high concentration. The addition amount is preferably 0.3 to 5% by weight based on the total amount of all components of the film.

If necessary, the above thermoplastic resin may contain an antioxidant, a heat stabilizer, an ultraviolet absorber, a plasticizer, a pigment, an antistatic agent, a lubricant, a crystal nucleating agent, and the like.

The method for producing the thermoplastic resin is not particularly limited. For example, in the case of polyester, it can be produced by a conventionally known transesterification method or direct polymerization method. Further, in order to increase the molecular weight, it can be produced by a solid phase polymerization method.

The surface wetting tension of at least one surface of the thermoplastic resin film specified in JIS-K-6768 is preferably 420 μN or more. There is no limitation on the surface treatment means for the surface wetting tension to be 420 μN or more, and examples thereof include a corona discharge treatment method, a primer treatment method, an ozone treatment method, a plasma treatment method, an electron irradiation treatment method, a flame treatment method, and a chemical treatment. Treatment methods and the like. In particular, a corona treatment method is recommended and is a preferred embodiment. When the surface wetting tension is 420 μN or more, the film has a strong adhesive force when laminating to a metal plate, and the film hardly peels off from the metal plate in the can-making process and / or various processes after the can-making. preferable.

Further, it is preferable that each of the thermoplastic resin films has a shrinkage ratio of 5% or less after a heat treatment at 150 ° C. for 30 minutes in a longitudinal direction and a transverse direction. The means for reducing the shrinkage to 5% or less is not particularly limited. For example, a so-called heat fixing step is provided in the film manufacturing process to reduce the shrinkage stress of the film, Examples include setting a film forming speed condition and setting a film winding condition in which the contraction force remaining in the film is reduced by minimizing the tension of the film during film formation. In particular, heat setting is the most recommended and preferred embodiment.

When the shrinkage is 5% or less, a uniform laminated metal plate can be obtained without causing wrinkles caused by a heat shrinkage phenomenon when laminating the metal plate.
In addition to the above, from the viewpoint of heat resistance, it is also a preferable embodiment to appropriately provide a heat-resistant overcoat layer for imparting heat resistance, and blend known additives such as a heat stabilizer.

The thermoplastic resin film of the present invention may be either an unstretched film or a stretched film. In the case of a stretched film, any of uniaxial stretching and biaxial stretching may be used, but a biaxially stretched film is preferred from the viewpoint of isotropicity. The method for producing the film is not limited at all. For example, in the case of a stretched film, a conventionally known method such as a T-die method and a tubular method can be applied. Furthermore, the thickness of the thermoplastic resin film is preferably 4 to 50 μm.
m, more preferably 5 to 30 μm.

The laminated metal plate of the present invention can be obtained by laminating the above-mentioned film for laminating a metal plate on a metal plate. Metal plates used are tin,
Tin-free steel, aluminum and the like.
The method of laminating the film on a metal plate is not particularly limited, and a conventionally known dry lamination method, thermal lamination method, or the like can be employed. As the lamination method, for example, there is a method of laminating an adhesive layer on a film after laminating an adhesive layer on the film, forming an adhesive layer on the film in a partially cured state, and completely laminating the adhesive layer on the metal plate. It is preferable to use a method using heat, light, an electron beam, or the like. In addition, the adhesive used in the above method is to use a curable resin so that the adhesive is firmly bonded to the metal plate and does not lose the bonding force due to seam welding during baking or subsequent boiling or retorting. preferable. In particular,
For example, an epoxy resin, a polyurethane resin, a polyester resin, a polyester polyurethane resin, an isocyanate resin or the like, or various modified resins thereof may be used. As another method, for example, there is a method in which a multilayer film in which a low-melting polyester resin is laminated on the upper layer of the film is produced by a co-extrusion method, and thermal lamination is performed by heating a metal plate with electric current. The lamination of the film to the metal plate may be on one side or both sides. For double-sided lamination,
Lamination may be performed simultaneously or sequentially.

The metal container of the present invention can be obtained by molding using the above-mentioned laminated metal plate. The method for forming the metal container is not particularly limited. Also, the shape of the metal container is not particularly limited, and for example, a so-called 3 is suitable for filling a food product such as a retort food or a coffee beverage, and the content is filled by winding a top lid. Piece cans are preferred.

[0036]

EXAMPLES Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples and may be carried out without departing from the scope described above. Also fall within the technical scope of the present invention. In the examples, “parts” means “parts by weight”, and “%” means “% by weight”. Each measurement item followed the following method.

(1) Pinhole Detection Method (High Voltage Application Method) In the case of detecting a 0.1 mmφ pinhole, a 0.1 mmφ pinhole is formed in the film, and the pinhole is used in the apparatus shown in FIG. The gap between the detection unit electrode and the detection unit roller and the applied voltage are appropriately determined. In the case of this embodiment, the gap between the detection unit electrode and the detection unit roller is 0.2 mm, the applied voltage is 2.4 kV, and the traveling speed is 50 m / min. Under these conditions, a running / detection inspection was performed on a film sample roll wound in a roll shape having a width of 1,000 mm and a length of 1,000 m.

(2) Manufacturing method of laminated metal plate (laminated steel plate) The surface of the film to be laminated with metal is subjected to a corona discharge treatment, and an adhesive (polyurethane-based adhesive “Toyo Ink Co., Ltd. And a curing agent) were coated at a solid content of 4 g / m ² , dried, and aged at 40 ° C. for 24 hours to obtain a film for lamination. The laminating film was laminated on a degreased cold-rolled steel sheet by a thermal lamination method to obtain a laminated steel sheet.

(3) Rust prevention test method After obtaining a laminated film inspected according to the inspection method of (1), a laminated metal plate is produced according to the method of (2), and this is subjected to a can-making process. It was formed into a metal container. Fill a can with 1% NaCl aqueous solution
Observation of the state of rust generation after one month and appearance inspection of the can were carried out.

(4) Surface Wetting Tension Test Method The surface wetting tension of the surface to be laminated on a metal plate is measured according to JIS-
The test was performed according to K-6768.

(5) Heat Shrinkage Measurement Method Longitudinal direction (MD direction) of film for lamination on metal plate
And the heat shrinkage in the transverse direction (TD direction)
The measurement was performed according to -2318.

Example 1 Polymethyl methacrylate particles (spherical; average particle size: 3.0 μm) crosslinked with 0.1% of agglomeration type silica (average particle size: 1.5 μm) and trimethylolpropane trimethacrylate Contains 0% and has an intrinsic viscosity of 0.70
A mixture of 97 parts of polyethylene terephthalate and 3 parts of polyethylene terephthalate-polytetramethylene glycol ether block copolymer was adjusted to a moisture content of 30 ppm by a vacuum drying step, and then melt-extruded by a T-die method to form an amorphous sheet. . At this time, during the resin melting step, a two-stage type melt filter having a pore size of 20 μm and 10 μm is provided. Further, after that, the amorphous sheet is vertically 3.5 times at 90 ° C.
The film was stretched 3.5 times in the transverse direction, heat-set at 200 ° C., and both surfaces of the film were subjected to a surface treatment using a corona discharge treatment method to obtain a polyester film having a thickness of 12 μm. The inspection result using the inspection method of (1) is 0.1 m in diameter.
0 / 20,000m pinhole detection number over mφ
^{Was 2} . A double-sided laminated steel sheet was obtained from the above polyester film according to the method (2). Thereafter, a test regarding rust generation was performed by the method (3). Table 1 shows these characteristics. The film for lamination on a metal plate, the laminated steel plate, and the metal container obtained in this example are excellent in corrosion resistance, and the number of rusted cans is 0 / 1,000,000 cans. The appearance of all the cans remained beautiful, and the film was of high commercial value.

COMPARATIVE EXAMPLE 1 In the resin melting step, a resin having a two-stage melt filter having a pore size of 80 μm and 60 μm was used.
As a result, the number of detected pinholes with a diameter of 0.2 mmφ is 1
A laminated steel plate was obtained in the same manner as in Example 1 except that a polyester-based film having a capacity of 1,000 m ² was used, and a test on rust generation was performed. Table 1 shows these characteristics. The film for lamination on a metal plate, the laminated steel plate, and the metal container obtained in the present comparative example had a number of rusted cans of 1 / 50,000 cans. Existence confirmed. As described above, the film was rusted on the metal can material due to the presence of the pinhole, and significantly deteriorated the appearance, and was of low commercial value.

Comparative Example 2 In the resin melting step, pore diameters of 100 μm and 80 μm
Example 1 was used except that a polyester film having a diameter of 0.3 mmφ and the number of detected pinholes was 5 / 1,000 m ² was used. A laminated steel plate was obtained in the same manner as described above, and a test on rust generation was performed. Table 1 shows these characteristics. The film and the laminated steel sheet and the metal container for lamination to the metal plate obtained in the present comparative example,
The number of rusted cans is 4 / 50,000 cans,
The presence of a pinhole was confirmed in the defective can. In this way, the film causes rust on the metal can material due to the presence of the pinhole, and significantly deteriorates the appearance.
The product value was low.

Comparative Example 3 A polyester resin mixture having a water content of 500 ppm was used. As a result, a polyester film having a diameter of 0.2 mmφ and a pinhole detection number of 10 / 1,000 m ² was used. Except for the above, a laminated steel plate was obtained in the same manner as in Example 1, and a test on rust generation was performed.
Table 1 shows these characteristics. The film for lamination on a metal plate, the laminated steel plate, and the metal container obtained in this comparative example had a number of rusted cans of 9 / 50,000.
The number of cans was 0, and the presence of pinholes was confirmed in the cans that failed. As described above, the film was rusted on the metal can material due to the presence of the pinhole, and significantly deteriorated the appearance, and was of low commercial value.

Comparative Example 4 A laminated steel sheet was obtained in the same manner as in Comparative Example 1 except that a corona discharge treatment was not performed and a polyester film having a surface wetting tension of 380 μN was used. Table 1 shows these characteristics.
Shown in The film for lamination and the laminated steel sheet to the metal plate obtained in this comparative example have pinholes,
In addition, the film peeled off during the can-making process, and was of low practicality.

Comparative Example 5 The heat setting temperature was 135 ° C., and the heat shrinkage in the horizontal direction was 8%.
Comparative Example 1 except that a polyester film was used.
A laminated steel sheet was obtained in the same manner as described above. Table 1 shows these characteristics. The film for lamination on a metal plate and the laminated steel plate obtained in the present comparative example had pinholes, wrinkles occurred in the laminating step, and were of low practicality. Table 1 shows the results of Example 1 and Comparative Examples 1 to 5.

[0048]

[Table 1]

Example 2 When a rust prevention test was carried out on a sample having one pinhole having a diameter of 0.05 mm per can, no rust was observed after one month. The product had high commercial value without significant deterioration.

Comparative Example 6 A rust prevention test was carried out on a sample having a pinhole having a diameter of 0.1 mm per 1 / can. As a result, rust was observed after one month, and the appearance due to the rust was remarkable. Deterioration was confirmed, and the product value was low.

Comparative Example 7 A rust prevention test was carried out on a sample having one pinhole having a diameter of 0.2 mm per can. As a result, rust was observed after one month, and the appearance due to rust was remarkable. Deterioration was confirmed, and the product value was low.

[0052]

The metal plate obtained by laminating the film for laminating on the metal plate of the present invention and the metal container made from this metal plate have a remarkable deterioration in appearance due to the generation of rust on the metal can material and aesthetic design. It is possible to provide a cosmetic metal container that is extremely excellent in aesthetic design and has a high protective effect on food products, with little loss, deterioration of food products due to transfer of rust components to food products, and can provide, for example, soft drinks, beer, canned foods. It can be suitably used as such a metal can material.

[Brief description of the drawings]

FIG. 1 is a diagram showing an apparatus and a method for detecting a pinhole in a film.

[Explanation of symbols]

1: Film before unwinding shaft and pinhole detection test 2: Guide roller 3: Detector roller 4: Detecting electrode 5: Guide roller 6: Press roller 7: Film after winding shaft and pinhole detection test 8: High Voltage generator and pinhole detection data processor 9: Cable connection

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tsutomu Isaka 2-2-2, Dojimahama, Kita-ku, Osaka Toyobo Co., Ltd.

Claims (2)

[Claims] 1. A metal plate laminating film containing a thermoplastic resin, wherein a pinhole having a diameter of 0.1 mmφ or more does not exist at least in a portion to be laminated to a metal. Laminated metal plate. 2. A metal plate formed by laminating a film for laminating a metal plate containing a thermoplastic resin, wherein a pinhole having a diameter of 0.1 mm or more does not exist at least in a portion to be laminated to the metal. A metal container characterized in that: